A Study of the Divacancy in Irradiated Silicon Using Infrared Spectroscopy and Infrared Photoconductivity Measurements

The annealing behavior and the uniaxial stress response of radiation-induced defects in Si causing the 1.8-, 3.3-, and 3.9- ¿ infrared absorption bands, and the EC-0.39 and Ec-0.54eV photoconductivity levels were studied after 1.5 and 45MeV electron and fast neutron irradiation. In addition, photoconductivity associated with the 0.32eV (3.9¿) band is reported. Correlating all of the above results with those obtained previously in electron paramagnetic resonance (EPR) studies leads to the conclusion that the defect responsible is the divacancy, i. e., one in which two adjacent Si atoms are knocked out of the lattice to form the intrinsic divacancy defect. The predictions of the divacancy model of Watkins and Corbett(l) is found to give good agreement with the experimental results, in particular as the results are correlated on a microscopic scale with EPR measurements.